This invention relates to the cleaning of an enlargement lens in a photo-processing apparatus used in a photo laboratory or the like.
A schematic construction of a conventional photo-processing apparatus 1 is shown in FIG. 10. A rolled photosensitive material (printing paper) 10 is fed inside a dark room 2 from an upper part of the apparatus 1, cut to a specified length by a cutter 4, and then placed on an exposure table 3 provided substantially at 45.degree. to the ground. An enlargement lens unit 20 is arranged such that an optic axis L thereof is normal to the exposure table 3, i.e., substantially at 45.degree. to the ground in a direction opposite to the exposure table 3. A light source 11 is so arranged via a mirror unit 12 as to be substantially normal to the optic axis L of the enlargement lens unit 20. Between the light source 11 and the enlargement lens unit 20 is provided a film feeding mechanism (not shown) for feeding a negative film. Further, an operation panel 13, a monitor display device 14 and the like are provided in vicinity of the light source 11 and the enlargement lens unit 20. The exposed photosensitive material 10 is conveyed to a developing unit 30 via a conveying mechanism 5 including a belt and the like, and is discharged onto the top of the apparatus 1 after being developed, fixed, water-washed and dried.
Next, the detail of the enlargement lens unit in the conventional photo-processing apparatus is shown in FIG. 11. The enlargement lens unit 20 includes a lens moving deck 21 which is movable along a specified direction X-X' (e.g., a direction normal to the plane of FIG. 10) by, e.g., a ball screw mechanism or a belt driving mechanism (not shown), a main lens 22 such as a zoom lens placed on the lens moving deck 21, a mirror 23 and an auxiliary lens 24 such as a single-focus lens. The lens moving deck 21 is divided into three areas. The mirror 23 is placed on a mirror mount area B in the middle and the main and auxiliary lenses 22, 24 are placed on first and second lens mount areas A, C at the opposite sides of the mirror mount area B, respectively.
The main lens 22 such as a zoom lens enables the processing of pictures of two different sizes by one apparatus by suitably switching a focal length (angle of view), for example, in the case that a film having a 135 size includes images photographed in normal photographing mode and those photographed in panorama photographing mode. The auxiliary lens 24 such as a single-focus lens is used, for example, in the case that a film has a large frame size such as 120 or an enlargement magnification is large. The mirror 23 is adapted to bend a propagation direction of light having transmitted through an aperture 50 and a film placed so as to face the aperture 50 substantially at 90.degree. to introduce the light to an optical sensor 25. The optical sensor 25 detects the state of the film, i.e., the respective color components of yellow, magenta and cyan which are complementary colors of three primary colors (red, blue, green). A ratio of the respective colors, an exposure time and other factors are determined based on an output of the optical sensor 25.
However, the production of fine paper dust is unavoidable in the aforementioned conventional photo-processing apparatus since the photosensitive material 10 is cut to a specified length by the cutter 4. Thus, the paper dust deposits on the surface of the enlargement lens (the main lens 22 or the auxiliary lens 24) by continuously using the apparatus 1 for a long time. Although the dark room 2 and the developing unit 30 are separated, a mist of developer and/or lubricant flying in the air via a clearance provided between the dark room 2 and the developing unit 30 to feed the photosensitive material 10 deposits on the surface of the enlargement lens. Therefore, the surfaces of the enlargement lenses need to be cleaned at regular intervals.
In the conventional photo-processing apparatus, after the photosensitive material 10 is retracted from the dark 2, a door (not shown) of the dark room 2 is opened and an operator slips into the dark room 2 to clean the surfaces of the enlargement lenses provided in the enlargement lens unit 20 using a brush, blower, cloth or the like. Operability is very poor since a work space is very narrow and dark. Further, since it is difficult to see the surfaces of the lenses during the cleaning, it is difficult to completely clean the lens surfaces.